Not what I was saying...
Let's say the web page is in the root directory of
https://www.greenguysite.com (could be http:// as well)
If the images are stored in a folder named images then a relative image URL would looks like:
Code:
<img src="images/picture.jpg">
as opposed to an absolute image url:
Code:
<img src="https://www.greenguysite.com/images/picture.jpg">
The two sponsor examples you posted are pulling images from a subdomain, so the relative url isn't an option.